Konstantin Sergeyevich Stanislavsky (January 17 [O.S. 5 January] 1863 – August 7, 1938), was a director and acting innovator, responsible for a great deal of the acting technique used during the 20th century, all over the world.

Stanislavsky was born Konstantin Sergeyevich Alexeyev in Moscow to a wealthy family in 1863. He came from a prosperous Russian family who manufactured gold and silver braiding for military decorations and uniforms. Marie Varley, his grandmother, was a touring French actress and the only member of his family from an artistic background. Stanislavsky had eight siblings, who joined the young boy in creating elaborate theatricals on birthdays and holidays. The family created its own amateur theatre and Stanislavsky frequently acted in these miniature shows, usually meant for birthdays or holidays. At eight years old, Stanislavsky became interested in the circus, and often directed and starred in his own imaginary circuses. Another passion for the young Stanislavsky was puppetry, where he put on scenes from The Corsair and The Stone Guest. With puppetry, he learned to hone in on his love of detail--a quality Stanislavsky would incorporate in his directing later on in life with the Moscow Art Theatre. At fourteen, Stanislavsky started what would be numbers of notebooks filled with observations, aphorisms and problems. As a blossoming actor, Stanislavsky would dress as a tramp and go down to railroad yards, or disguise himself as a gypsy. Konstantin took a firm decision, despite the opposition of his father, to study theatre.